1. Field of the Invention
The present invention relates to a management system in a field computing field.
2. Related Art
A system of field computing for collecting information from field equipment, such as a sensor or an actuator, which is located in a field, to perform processing has been used not only in a business field but also in a wide area monitoring system, a distributed control system, and the like (see, for example, JP-A 2006-91961). In this system, a computer (such as a personal computer (PC)) connected to a plurality of pieces of field equipment collects the information from the field equipment to perform the processing by executing an application (program) on the computer.
FIG. 8 shows the configuration of a conventional control system 1γ. As shown in FIG. 8, the control system 1γ is configured to include PCs 7A and 7B, a gateway apparatus 8, a database 51, and sensors 31-33 and actuators 41-44 as field equipment. The database 51 is connected to the PC 7B. The PCs 7A and 7B and the gateway apparatus 8 are connected to each other by communication connection through a communication network N1. The gateway apparatus 8, the sensors 31-33, and the actuators 41-44 are connected to one another by communication connection through a communication network N2.
In the control system 1γ, the PC 7A obtains the measured values and the status values of the field equipment (the sensors 31-33 and the actuators 41-44) by means of the application (programs) of the field computing field which applications are executed by the PC 7A, and the PC 7A stores the obtained values into the database 51. Moreover, the applications of the PC 7A execute necessary operations, and returns information to the field equipment side according to the situation. The PC 7B similarly operates.
Generally, the applications of the PC 7A does not obtain data from a target piece of field equipment in real time. It is determined beforehand that the PC 7A uses the information of which piece of field equipment, and the PC 7A frequently obtains the pieces of information of the field equipment from the gateway apparatus 8, such as a digital control system (DCS), or the database installed in a not shown host computer.
The system for accessing a database frequently changes according to a communication object and a system configuration. Accordingly, the applications of the PC 7A has previously obtained the information concerning where information is located, what kind of the information it is, and how the communication with the information can be performed. The PC 7A obtains information by accessing these gateway apparatus 8 and database 51 through a given interface, and performs control processing by given algorithm.
Moreover, because the information exchanges between the PC 7A and the field equipment cannot be performed by a specific communication system, the equipment frequently performs communications with another system or another computer through the gateway apparatus 8.
The field equipment has been frequently connected with specific communication networks, however, in conventional control systems. For example, when the communication network N2 is a specific one, then it is frequently difficult for the PC 7A, on which the applications operate, to access the field equipment. Only the information stored in the given gateway apparatus 8, the database 51, or the like beforehand has been available for (the applications of) the PC 7A. Moreover, it has been necessary for the PC 7A to be aware of the interface for accessing the gateway apparatus 8, the database 51, and the like beforehand.
When these situations are examined from the points of view of the applications of the PC 7A, the situations have the following problems:
(1) it is not possible to access the field equipment in real time to obtain and set just the current information;
(2) there can be used only the information that exists at the positions at which the locations of data and the interfaces have been aware of beforehand; and
(3) it is necessary to be aware of the interfaces for accessing the gateway apparatus, the database, and the like beforehand.
In a word, the combination of the side of supplying information and the side of using the information must be determined in advance.
Consequently, when the kind of the necessary information and the method (e.g., interface) of supplying the information are different, then the application (programs) must be remade. Moreover, even when the algorithm processing information is altered only a little, the whole application (program) must be remade. Accordingly, when the kind of information or the access means to the information is different even when the functions and the objects of applications are the same, it is necessary to develop a plurality of application (programs) that are almost the same and similar to each other. Moreover, it is also necessary to manage the plurality of application (programs).
Because it is determined beforehand which data is obtained from which piece of equipment and how the data is processed, it is difficult to dynamically change the processing algorithm and the obtainment source of the data in order to cope with various requirements of a user.
A system called as a service oriented architecture (SOA) combining services to construct an application has been spreading mainly around a business system field. In the field computing field, however, the communications with equipment are limited to the use of a specific system. Owing to the limitation, the services are provided by the functions of the field equipment. Consequently, the present state is that the applications based on the SOA are not constructed yet. Furthermore, a system using the SOA in order to dynamically change data and processing systems are not realized yet.